Refrigerating apparatus



J. F. HOFFMAN.

REFRIGERATING APPARATUS.

APPLICATION FILED JUNE 26, I918.

Patented Aug. 24, 1920.

3 SHEE SSHEE1Z.

1: MIN ihAnInW- HNVENTIER:

J. F. HOFFMAN.

REFRIGERATING APPARATUS.

APPLICATION FILED JUNE 26, I918.

Patented Aug. 24, 1920.

3 SHEEIS$.HEET 3.

' JOHN F. HOFFMAN, or ROCHESTER, NEW YORK.

REFRIGERATING APPARATUS.

Application filed June 2 6,

To all whom it may concern:

.Be it known that I, JOHN F. HOFFMAN, a refrigerating engineer,citize1r of the United States, and resident of Rochester, in the county of Monroe and State of New York,

' have invented certain new and useful Improvements in Refrigerating Apparatus, of which the following is a specification.

' The present invention relates to refrigcrating apparatus and more particularly to the type employing a fluid, such as ammonia, which is liquefied and then evaporated in contact with a refrigeratin or cooling surface to produce the desired degree of temperature, an object of this invention being to provide for automatically maintaining a substantially constant temperature in the cooling or refrigerating surface notwithstanding the varying demands upon such surface.

To this and otherends, the invention consists of certain parts. and combinations of parts all of which will be hereinafter described, the novel features being pointed out in the appended claims.

In the drawings Figure 1 shows' diagrammatically a refrigerating system embodying the present invention- Fig. 2 is a sectional View through the valve. which controls the supply of liquid to the refrigerating or cooling surface, the valve being shown closed against one of its seats;

. Fig. 3 is a section on the line 3-3, Fig. 2;

Fig. 4 is a detail sectional View similar to Fig. 1,'showing the valve closed against another of its, seats; I

- Fig. 5 is a sectional View through a valve which controls the quantity of the water used to condense theammonia as well as the temperature of the system; and

Fig. 6 is a fragmentary View, showing the mannerin which the stopping of the system is produced.

A well known type of refrigerating sys-" tem' now in use embodies the main suction line 1 leading to the compressor 2, which may be driven in any suitable manner, as by an electric motor 3. From the 'compressor a discharge line 4 leads to anfoil .tr-ap, not shown, and from the latter to a condenser. This condenser embodies inner tubes 5 surrounded by outer tubes 6 with I Specification of Letters Patent.

Patented Aug. 24, 1920.

1918. Serial N0. 242,054.

spaces between them, and inner tubes conducting cooling water from a supply pipe 7 through the outer tubes and being, in turn,

connected with a drain or discharge pipe 8 which leads through the jacket of the compressor 2, and from the jacket, by way of a drain pipe 9, to any suitableplace, such as a sewer. The spaces between the inner tubes and the outer tubes 6 of the condenser serve to conduct the ammonia gas which, being in a compressed state and contacting with the water tubes 5, which are of lower temperature, condenses and is discharged into the ammonia receiver 10 by way of the pipe 11.

From the ammonia receiver a supply pipe 12 extends to one or more cooling surfaces 13. which are designed as usual to perform any desired work, such as making ice, or cooling beer, water, or other fluid, and also incooling perishable foods.

A refrigerating plant or system is constructed to produce a certain capacity, and this capacity is obtained by maintaining a certain degree of saturation of the gas in the cooling surface. The nearer this saturation is maintained. the more efiicient will be the refrigerating system. If the saturation falls below this degree, that is, less saturated, then a dry condition exists in the machine and the ammonia gas I will enter the compressor slightly superheated, whereas, if this saturation be increased, a wet condition will exist and the ammonia gas entering the compressor will be accompanied by sufiicient liquid to absorb the heat of the compressor, so that the temperature of the discharge will be that at which the ammonia gas accompanied by. suff cient liquid ammonia will condense under the pressure to which it has been compressed, bothyof these conditions rendering therefrigerating system less efiicient.

According to this I invention, provision is made whereby the degree of saturation of Y the gas for which the plant is designed is automatically maintained constant, so that a-maximum efficienc is secured. This result is referably ohtained bycontrolling the liquid supply tothecooling surfaces by thermostats which are affected by the. temperatures 'of the discharges from the cooling surfaces, the liquid supply also beingcontrolled by the pressure in the liquid supply,

provision being madelfor maintaining this y v pressure constant, preferably by controlling the temperature of the outlet water from the condenser.

To secure the above results, near each cooling surface a valve casingis introduced in the liquid supply 12, said casing having an inlet port 14 and an outlet port 15 with a communicatin passage between them. In this passage is preferably arranged a valve chamber 16' with valve'seats 17 and 18, re spectivcly, for engagement by a valve member 19, said valve member having a shoulder 20 for engagement with the seat 17 and a tapered portion 21 for engagement with the seat 18. When the valve member is in one extreme position, it cooperates with the seat 17 to close the passageway, and when in the other extreme position, it cooperates with the seat 18 to close the passageway. A spring 22 'isvmounted within a chamber 23.

in the valve casing and-acts upona collar 24 which is secured to a stem 25 that extends from the valve member 19, such spring tending to hold the shoulder 20 of the valve ber 23.

To the end that the'valve member 19 may be held away from the scat 17 under the pressure within the supply pipe 12, the valve casing may be provided with a chamber 28 between the inlet 14 and the valve seat '18,

shoulder 20 will move toward the seat 17 under the action of the spring 22.

The. valve member 19 may also be controlled by the temperature of the fluid in the main line 1, into which the cooling surfaces discharge, and to this end a coupling memv ber 31 may be introduced into the main line 1 in proximity to each cooling surface 13,

and in this coupling member, which may be in the form of a T, a thermostat may be introduced. In this instance, this thermostat embodies a casting 32 fitted to the central arm ofthe T 31 to close said arm and having a ,projecting chamber 33 in which a readily= -,expansible fluid 34, such as li uid ammonia, is placed. The casting 32 also HIS a flanged portion 35, which is bolted at 36 to the casing of the valve member 19, and acts .supply pipe 15 is automatically maintained constant during the normal operation of the machine, consequently, it is possible to so adjust the valve tension that the valve member 19 lies out of contact with both of the seats 17 and 18, subject only to variations in the temperature of the fluid in the main line 1, it being understood, of course, that the adjustment in the first instance is effected for a certain temperature in the main line. It is apparent that a reduction in the temperature of'the main line will cause the valve member 19 to move toward the seat 18, thus either closing the supply pipe 12 or reducing the flow therethrough while an increase in temperature in the main line I will increase the flow through the supply pipe 12. How- "ever, should the pressure in thesupply plpe be reduced, then the valve shoulder 20 will cooperate with the seat 17 and out 01f th supply completely. K

To the end that fine particles in the liquid supply shall not reach the seats of the valve' 19, a strainer device 39 may be introduced in the liquid supply pipe to collect all such particles.

For the purpose of controlling the pressure in the liquid supply 12, the mechanism shown in detail in Figs. 5 and 6 is employed. This mechanism connects with the outlet or drain or discharge pipe 8 of the condenser and comprises a casing 40 interposed in the drain pipe 8 and having a valve member 41 which, in this instance, is of a reciprocating form and cooperates with two openings 42 in a partition 43 within the casing 40. A spring 44 has a tendency to seat the valve, while a thermostat afl'ected by the discharged water monia is contained within the chamber 45.

and acts upon the diaphragm 47 to move the latter with the different changes in temperature in the discharge lwater. Connection between this diaphragm 47 and the valve 41 tions in the temperatureof the discharge water willoperate the valve 41 to varythe flow of the discharge water through the valve casing, and in this way maintain a substantially constant temperature under the varying load conditions. By maintaining the temperature of the condenser constant, the pressure of the liquid in the supply pipe 12 will also be maintained constant. Ordinarily, the temperature of the discharge water from the condenser should be main-' tained at substantially 90 Fahr.

There also may be provided means controlled by the temperature of the discharge water for automatically stopping the compressor whenever'the supply of water to the ammonia condenser is cut off while'the machine is in operation. The cutting off of the main water supplywill immediately cause an extra amount of heat in the discharge Water pipe 8, thus affecting the thermostat 4.5 to an extreme degree, causing thelever 52 to move upwardly beyond its normal path .of operation. To utilize this extreme movement of the lever 52 for stopping the compressor, a mechanism coiiperates with said lever and comprises, in this instance, a plunger 57 normally held in its lowermost position by a spring 58 and having its upper end bearing against an intermediate one of a series of balls 59 which are arranged within a casing 60 secured to the casting 48. At opposite ends of the series of balls plungers 61 and 62 are arranged, each plun ger being acted upon by a spring 63 surrounding such plunger. The casing 60 is provided with a chamber 64 directly above the ball 59 that is engaged by the plunger 57 v and in this chamber 64 a ball 65 bearing against that ball 59 engaged by the plunger 5 This ball 65 is, in-turn, engaged by the projection 66 on a diaphragm 67 which is controlled by fluid within the chamber 68 above the diaphragm. The chamber 68 communicates by a by-pass 69 with the valve casing 40, so that the diaphragm 67 is sub- ]ected to the pressure of the fluid or water within the discharge pipe 8. At the time that the thermostatic device is operated under the increased temperature to shift the lever 52, so that the latter engages the plunger 57, the pressure in the chamber 68 decreases, due to the lack of water in the valve casing 40, and, as a consequence, the dia phragm 67 is free to move upwardly, thus offering no resistance to the movement of the ball and the ball 59 that is acted upon by the plunger 57 sothat both balls shift upwardly to the chamber 64 under the action of the plunger 57, and this movement is facilitated by the springs 63 acting upon the plunger 61. The plunger 61" may be utilized for engaging .the contact 70 with the contact 71 in order to close the circuit 72 of an alarm bell 73, whereas the plunger 62 may be connected to the blade 74 of a switch which controls the circuit of the electric motor 3, thus not only giving an alarm but stopping the motor which drives the compressor 2. In Fig. 6, the parts are shown in the positions they occupy when the central ball 59 has been shifted.

. From the foregoing it will be seen that there has been provided a valve for controlling the liquid supply to a cooling surject to the pressure of the supply liquid as Well as the temperature of the discharge from the cooling surface, thus making it possible to supply an amount of ammonia to the cooling surface inproportion'to the demandof such surface. and thereby making it possible to run the plantwith greater economy. The refrigerant leaves the cooling surface in a non-saturated condition and enters the compressor in a dry condition so that greater work power is secured-from the compressor. As each coollng surface has .85 face of a refrigerating system which is subvary to any great extent it would interfere with the power operator and real regulator of the suction temperature'controlling device, and it is for this reason that the liquid supply valve is affected by the pressure in the'supply pipe. It will be noted that this pressure is maintained constant by controlling the dischar e of the cooling water of the condenser.

away at a temperature of about 90 Fahr. It can therefore be used for thermostatically controlling its discharge, as by opening the valve wide the water will fiow freely and.

his water becomes heated-- from the heat of compression and is carried pressure of the liquid supply will also increase. The shutting off of the water increases the temperature and increases the pressure in the discharge so that the compressor is stopped and an alarm is given. What I claim as my invention and desire to secure by Letters Patent is 1. In a refrigerating system, a cooling surface, and a valve for controlling the liquid supply to said surface controlled jointly by the pressure of the liquid supply and the temperature of the discharge from the cooling surface and having provision for cutting off said liquid supply with a reduction of pressure in the liquid supply.-

2. In a refrigerating system, a cooling surface, a valve for .controlling the liquid supply to said surface controlled by the temperature of the discharge from said surface, and means for automatically maintaining constant the pressure of the liquid in the liquid supply leading to said surface.

3. In a refrigerating system, a cooling surface, a valve for controlling the liquid supply to said surface controlled by the temperature of the discharge from the cooling surface, and separate thermostatic means for automatically maintaining constant the pressure of the liquid in the liquid supply leading to said surface.

4. In a refrigerating system, a cooling surface, a valve for controlling the liquid supply to said surface, a condenser having a cooling water discharge and connected with said surface, a valve for controlling said cooling water discharge, and thermostatic means for moving the valve in accordance with the temperature of the discharge water to control the pressure in the liquid supply leading to the cooling-surface.

5. In a refrigeratlng system, a cooling surface, a valve for controlling the liquid supply to saidsurface controlled jointly by the pressure of the liquid supply and the temperature of'the discharge from the cooling surface, and means for automatically maintaining constant the pressure of the liquid in the'liquid supply. I

6. Ina refrigerating system, a cooling] surface, a valve for controlling the liquid supply to said surface controlled jointly by the pressure of the liquid supply and the temperature of the discharge from the cooling surface, and separate thermostatic means for automatically maintaining constant the pressure of the-liquid in the liquid supply.

7. In a refrigerating system, a cooling surface, a valve for controlling the'llquid supply to said surface controlled jointly by the pressure of the liquid supply and the temperature ofthe discharge from thecooling surface, a condenser having a cooling water discharge, a valve controlling said discharge, andthermostatic means for movply upon the reduction of the pressure in the fluid supply.

9. In a refrigerating system, a cooling surface, and a valve for controlling the liquid to such cooling surface comprising two' seats, a valve member movable in one direction to cooperate with one seat and in the other direction to cooperate withthe other seat, a diaphragm connected to the valve member and subject to the inlet pressure of the liquid supply to hold the valve member from one of said seats, a spring for moving said valvemember toward the said seat, and a thermostat connected with said valve member to'control its position with reference to the other seat and subject to the temperature of thedischarge fluid from the cooling surface.

10. .In a refrigerating system, a cooling surface and a valve for controlling the flow of liquid to such cooling surface comprising two seats, a valve member for cooperating with either seat, a spring for moving the valve toward one seat, means subject to the pressure of the liquid supply for holding the valve away from said seat, and thermostatic means for controlling the position of the valve with reference to the other seat subject to the dischargetemperature of the cooling surface.

11. In a .refrigerating system, a cooling surface, and a valve for controlling the flow 'of liquid to such cooling surface comprising two seats, a valve member for cooperating with either of said seats, a spring for moving the valve member toward one of said seats, a diaphragm connected to the valve member and having one face thereof subject to the pressure of the liquid supply to, the cooling surface to hold the valve away from sald seat against the action of the spring, and a fluid thermostat subject opposition tothe supply liquid pressure to control the position of the valve member with reference to the other seat.

surface, and a valve for controllingjthe flow of liquid to such surface comprislng a valve seat, a valve member for cooperatlng with member and subject to tliepressure of the liquid supply, and an expansible fluid ther- I30 'to the temperature of' the discharge fluid from the cooling surface and having the fluid thereof acting on the diaphragm in the seat, a, diaphragm connected to the valve surface, a valve forcontrolling the supply to said surface controlled by the temperature of the discharge from the surface and also by the pressure of the liquid supply, a condenser for the liquid supply having a cooling water conductor, and automatic :means for controlling the discharge of the cooling Water to maintain the pressure of 5 the liquid supply constant.

14. In a refrigerating system, a cooling surface, a valve for controlling the liquid supply to said surface controlled by the temperature of the discharge from the surface, a. condenser for the liquid supply hav; ing a cooling ater conductor, a valve in the discharge-of the cooling Water conductor, and a thermostat affected by the disrcha-rgedrooling water and controlling the valve tomaintain a constant pressure in the coolin surface.

15. n amefrigerating system, a cooling surface, a valvefor controlling the flow of liquid to said surface controlled by the pressure of the liquid supply and also by the temperature of the discharge from the liquid supply, a condenser for the liquid supply having a cooling Water conductor, a valve in the discharge of the cooling Water conductor, anda thermostat affected .by the discharged cooling Water to maintain the pressure of the liquid'supply constant.

16. In a refrigerating system of the type embodying a cooling surface, a liquid sup ply and a condenser for the liquid supply having a cooling water conductor, and a compressor for delivering the fluid to the condenser; a stop mechanism for the compressor controlled by the temperature of the fluid in the cooling water conductor discharge. I

17 In a refrigerating system of the type embodying a cooling surface, a liquid supply and a condenser for the liquid supply having a cooling Water conductor and a compressor for delivering the fluid to the condenser; a stop mechanism for the compressorcontrolled by the temperature and the pressure of the fluid in the cooling Water conductor dischar e.

fOHN F, HOFFMAN. 

